Yarn severing mechanism for knitting machines



Nov. 17, 1964 B. F. COlLE 3,157,036 YARN SEVERING MECHANISM FOR KNITTING MACHINES Filed Oct. 18, 1961 2 Sheets-Sheet l PlE- l Stallion/16.3

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I N V EN TOR. fiery'amin flank/M Qai/e ATTORNEY.

Nov. 17, 1964 B. F. COlLE 3,157,036

YARN SEVERING MECHANISM FOR KNITTING MACHINES Filed Oct. 18, 1961 2 Sheets-Sheet 2 Fl l3-- :3

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I N V EN TOR. 569/0070? flank/in (Bi/e ATTORNEY.

United States Patent 3,157,036 YARN SEVERING MECHANISM FOR KNITTING MACHENES Benjamin Franklin Coile, Athens, Ga., assignor to Textile Machine Works, Wyomissing, Pa, a corporation of Pennsylvania Filed Get. 18, 1961, Ser. No. 145,834- Claims. (Cl. 66-140) This invention relates to multistation circular knitting machines and more particularly to means in such machines for severing and holding the ends of the severed yarns at the time they are removed from knitting position and for again severing the yarns at the'time they are returned to knitting position.

In circular knitting machines for knitting ladies seamless stockings and particularly such machines having main and auxiliary feeding stations, the stations are positioned 115 or more from each other around the needle circle and each station is provided with means for operating the needles and for moving the feed fingers for the yarns into and out of knitting position in the desired sequence. The machines are also provided with means for trimming both ingoing and outgoing yarns close to the needle circle at each of the stations which means includes an annular member having a toothed outer peripheral edge lying closely adjacent the needle circle. The annular member is rotatable with the needles and acts to engage and carry outgoing yarns of the main station between the elements of a clamping device and then to a cutter element cooperating with the teeth of the annular member to sever the yarn between the clamp and needles, the clamping device and cutting element being positioned between the main and auxiliary stations at a point closely adjacent the latter station. Likewise, the annular member engages and carries an ingoing yarn, while held by the clamping device, to the cutter element for severance between the needles and clamp device. The yarn trimming means also includes means for opening the clamp elements and suction means between the clamp device and cutter element for removing the Waste ends of the severed ingoing yarns from the clamp device. The yarns associated with the auxiliary station are clamped and severed by means similarly constructed and similarly arranged with respect to the auxiliary station.

In an attempt to adapt similar yarn trimming means to machines having four knitting stations, it was found that the limited space between the feed fingers and clamping and cutting means associated with each knitting station was insufficient to permit the annular member to carry the yarns to be severed into the clamping means thereby making the use of such clamping means and consequently the other features of the yarn trimming means impractical.

It is therefore an object ofthe instant invention to provide means in a circular knitting machine having a plurality of knitting stations for overcoming the above noted and other objections in severing and controlling the position of yarns when moved into and out of knitting position at each of the stations.

Another object of the invention is the provision of means in a circular knitting machine having a plurality of knitting stations for severing yarns associated with each of the knitting stations, the severing means including an annular toothed member and a cutting element associated with each station cooperating with the teeth of the annular member, the cutting element associated with each knitting station being adapted to sever yarns moved to knitting position at the same station and being also adapted to sever yarns moved out of knitting position at an adjacent station,

A further object of the invention is the provision of 3,157,036 Patented Nov. 17, 1964 means in a circular knitting machine having a plurality of knitting stations for severing both the ingoing and outgoing yarns associated with each of the knitting stations, and for holding the ends of the outgoing yarns following their severance, the yarn holding means comprising a suction tube for holding the ends of the yarns extending from the inactive feed fingers and for removing the waste end of yarns severed between the suction tube and the needles when the yarns are again returned to knitting position.

A still further object is the provision of suction means for holding the ends of the inactive yarns at each knitting station of a multifeed circular knitting machine, the suction means associated with each knitting station being so positioned in relation to the station as to hold the yarn on a radial line extending substantially between the center of the circle of needles and the feed fingers for the yarns.

Another object of the invention is the provision of yarn feeding and yarn severing means associated with each knitting station of a multistation circular knitting machine and means associated with each knitting station for guiding the yarns to the severing means, the guiding means at a station acting to guide the yarns to the severing means for severance at the same station when the yarns are moved to knitting position, and acting to guide the yarns to the severing means for severance at an adjacent station when the yarns are moved out of knitting position.

With these and other objects in view which will become apparent from the following detailed description of the illustrative embodiment of the invention shown in the accompanying drawings, the invention resides in the novel elements, features of construction and cooperation of parts, as hereinafter more particularly pointed out in the claims.

In the drawings:

FIGURE 1 is a top plan view of a portion of a multifeed circular knitting machine incorporating yarn severing and holding mechanism according to the instant invention;

FIG. 2 is an elevational view on an enlarged scale of certain of the mechanism as viewed in the direction of the arrows 2-2 of FIG. 1;

FIG. 3 is aview partially in plan and partially in cross section taken along the lines 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view on an enlarged scale taken in the direction of the arrows 44 of FIG. 3;

FIG. 5 is a view on an enlarged scale taken in the direction of the arrow 5 on FIG. 3; and

FIG. 6 is a sectional view on an enlarged scale as viewed in the direction of the arrowsv 6-6 of FIG. 2.

Referring to the drawings and particularly to FIG. 1 thereof, there is shown a multifeed circular knitting machine generally of the type shown in British Patent No. 790,141, published February 5, 1958, to which reference may be made for a more complete description as to its construction and operation. The machine illustrated includes a needle cylinder (not shown) adapted for both rotary and reciprocatory operation, four yarn feeding stations Nos. 1, 2, 3 and 4 each suitably incorporating a plurality of yarn fingers 15 for feeding yarns to a circular series of latch needles, indicated diagrammatically at 16 in FIG. 3, slidably carried in slots (not shown) in the needle cylinder, and pattern drums 17 for moving the fingers between active yarn feeding and inactive positions. The needles 16 are raised to latch clearing level through the medium of jacks and are lowered by stitch cams (not shown) to perform their stitch drawing movement generally in the manner described in said British patent.

The operation of the needles and other mechanisms U above referred to will not be further described herein except where their operation is required for a clear understanding of the instant invention.

The machine is also provided with a transfer dial mechanism 2% (FIG. 2) which includes a bed member 21 having guide walls 22 defining slots for guiding pairs of transfer bits 25 for radial movement in cooperation with the needles to to form the welt portions of stocking fabrics. The bed me ibcr 21 is secured to a shaft 26 supported in a housing member 27 of the dial mechanism 20 for rotation in synchronism with the needle cylinder. The transfer bits are moved radially in the slots of the bed member 21 by an outer cam ring 39 secured to a plate 31 carried in fixed position on the housing member 27 and by the usual vertically retractable earns 32 (FTGS. 3 and 4).

During knitting of stocking fabrics on the machine the yarn fingers are operated between active and inactive positions at each of the feed stations to move the yarns into and out of knitting position according to a predetermined sequence in a common manner. When a yarn is removed from knitting position by moving its yarn finger to inactive position the yarn between the finger and fabric is severed closely adjacent to the needles and clamped until it is again returned to knitting position. Also when the yarn is returned to knitting position it is again severed close to the first needle to take and knit it. The yarn severing means shown in connection with the instant invention is of the type generally shown in Patent No. 2,824,436, issued February 25, 1958 and includes an annulus 35 which is supported on the outer cam ring 3% for rotation relative thereto (FIG. 4). At its underside the annulus is provided with slots 36 interfittingly engaging the upper ends of the walls 22 (FIG. 5) of the bed member 21 whereby the annulus is rotated with the bed member. At its outer peripheral edge the annulus is provided with teeth 37 pitched in the direction of the counterclockwise or rotary movement of the needle cylinder. Cooperating with the upper surface of the teeth 37 of annulus 35 for severing the yarns at each of the stations 14 is a plate-like cutting element 49 having one end secured to the plate 31 as by screws 41 and having its other end or cutting edge 35 bent downwardly to resiliently engage the upper surface of the annulus (FIGS. 3 and 5). The cutting element at shown in FIG. 3 is that associated with station No. It and like cutting elements are similarly arranged at each of the other stations.

In the mechanism of said Patent'2,824,436, which was adapted to sever both the ingoing and outgoing yarns at a single knitting station, and the commercial adaptation of the same mechanism for machines having two knitting stations, the severing means associated with a knitting station is spaced a considerable distance from the yarn fingers at the station and is adapted to sever both the ingoing and outgoing yarns. The outgoing yarn, as it is carried to the severing point by the annulus, passes beneath a clamp member which acts to hold the yarn end after the severing operation and then beneath the open end of a suction tube located between the clamp and cutter member. Following the return of the yarn to knitting position the yarn is again carried to the severing point by the annulus and the yarn is severed be tween the first needle to take and knit it and the clamp member. The waste end of yarn is then withdrawn through the suction tube to a collecting chamber. In the machine of said patent and the commercial two-feed machine the space available to position the clamp, suction tube and cutting member in relation to the feeding position is such as to permit the proper holding of the yarns when out of action and the accurate feeding of the yarns to the needles when returned to knitting position. In the four-feed machine illustrated in the instant case the limited space between the closely spaced knitting stations is insufiicient to position the clamping means for holding the ends of the inactive yarns between the yarn feeding and severing means thereby making use of the prior mechanism in such four-feed machines impractical.

In order to hold and sever the ends of yarn in accordance with the instant invention the ends of the inactive yarns at each knitting station are held in the flow of air passing upwardly through the lower end of a tube 42 positioned between the yarn fingers 15 and the cutting element 49 associated with each station, and the upper ends of the tubes are connected to a manifold 45 carried on the housing member 27 of the dial mechanism 2! (FIG. 2). The manifold in turn is connected by a flexible tube 46 to a vacuum pump 47 or the like, indicated diagrammatically at 47 in FIG. 1, for inducing a continuous flow of air into the lower end of the tube. Preferably in its path between the manifold 45 and the pump 47 the air is caused to flow through a collecting chamber 5% which serves to catch the waste ends of the ingoing yarn as hereinafter set forth. As indicated in FIGS. 2, 3 and 6 the lower end of the tube 42 is flattened at 51 to form an elongated narrow opening 52 one end of which is flared outwardly to form an enlarged portion 55. The lower end of the tube 42 lies close to the upper surface of the plate 31 with the enlarged portion 55 positioned on or closely adjacent to a radial line extending from the center of the cylinder through the center of the knitting station and with the narrow opening 2 extending from the portion 55 in the direction of forward rotation of the needle cylinder of the machine. As indicated in FIG. 6, the enlarged portion 55 of the opening 52 permits the yarn ends extending from the feed fingers 15 to be held in side-byside relation by the flow of air passing through the tube 42.

In order that the ends of the inactive yarns will be of sufiicient length to insure that they will remain in the tube 42 and under tension by the fiow of air when the yarns are again moved to knitting position, the yarns at each of the stations upon being moved out of knitting position are prevented from being carried by the teeth 37 of the annulus 35 and severed by the cutting element at the same station but are instead carried by the annulus to the next adjacent station where they are severed by the cutting element associated with said adjacent station. For this purpose there is provided in association with the yarns at each station a guard plate 56 secured to the plate 31 of the dial mechanism 20 by screws 58. At its end adjacent the yarn held by the flow of air in the enlarged portion 55 of the tube 42, the plate 56 is provided with an upturned nose portion 57 having a lower camming surface 60 merging with a lip 61 which extends outwardly of and downwardly below the teeth 37 of the annulus 35 (FIGS. 2 and 3). As shown in FIG. 3, the lip 61 extends along the outer periphery of the toothed portion of the annulus 35 to extend outwardly of the cutting edge of the cutting element ll) associated with the station and then merges with an outer edge 62 of the plate 56 extending along an arc lying inwardly of the teeth 37 of the annulus to a point adjacent the nose portion 57 of the plate 56 associated with the adjacent station. A wire guide member 65 secured to each plate 56 by one of the screws 58 has a free end 66 substantially contacting tube 42 at a point above the upturned nose 57 of plate 56. The guide extends downwardly from the free end thereof to merge with a loop 67 overhanging the edge 62 of the plate 56. From the loop 67 the guide crosses the plate at a level spaced from the upper surface thereof and around a pin 70 fixed in vertical position in the plate to its holding screw 53.

When a yarn is removed from knitting position at a knitting station by moving its feed finger to raised in active position, the outgoing yarn is raised above the nose 57 of the plate 56 associated with the station and as the needles continue to rotate the yarn is carried by the last needle to knit it beneath the free end 66 of the guide member 65 which then acts to cam the yarn downwardly toward the upper surface of the plate 56 at a point beyond the nose 57 and lip 61 of the plate thereby missing the cutting member 4-6.5 associated with the station. Upon continued rotation of the needles the yarn passes beneath the loop 67 and into a tooth 37 of the annulus and the yarn is then carried thereby across the plate 56 beneath the nose 57 on the plate 56 associated with the adjacent knitting station and to the cutting element 40 associated with the latter station where it is severed. Hence, as illustrated in FIG. 3, a yarn removed from action at the station No. 4 is carried beneath the narrow opening 52 of the tube 42, between the guide member 65 and the upper surface of the plate 56 associated with station No. 4 and around the pin 7% therein, thence beneath the enlarged portion 55 of the opening 52 of the tube 42 at station No. 1 and to the cutting element 40 associated with the latter station. Immediately following severance of the yarn, due to the increased pressure of the air flowing into the more restricted narrow opening 52 at the end of the tube 42 associated with station No. 4, the end of the yarn is drawn therein by the flow of air and then into enlarged portion of the tube where it is held until it is again returned to knitting position.

Upon movement of a yarn to knitting position by lowering its feed finger to active position at a knitting station, the yarn is carried by the first needle to knit it into a tooth 37 of the annulus 35 and as the needle and annulus continue to rotate the yarn is carried beneath the nose 57 and lip 61 on the plate 56 and to the cutting element 49 associated With the same station to be severed. Immediately upon severance of the yarn between the tube 42 and the first needle the waste end of the yarn is Withdrawn through the tube by the flow of air to the collecting chamber 50.

From the foregoing it will be seen that the inactive yarns at each knitting station are held by the continuous flow of air passing through the suction tube associated with the station on a radial line extending substantially from the center of the needle cylinder through the circle of needles and the center of the station. Furthermore, it will be apparent that the path of the yarns at each station are so controlled that the yarns when moved out of knitting position will be guided to and severed by severing means associated with an adjacent knitting station and the yarns when again returned to knitting position will be guided to and severed by severing means asso ciated with the same knitting station as the yarns.

It will be understood that the improvement specifically shown and described by which the above results are obtained, can be changed and modified in various ways without departing from the invention herein disclosed and hereinafter claimed.

I claim:

1. In a circular knitting machine having a rotarily operated circle of needles, a plurality of knitting statons, guide fingers for feeding yarns to said needles at each of said stations, and means for moving said guide fingers thereat between active positions in which said fingers feed their yarn to said needles and inactive positions, in combination with means for severing yarns associated with each station, and yarn control means associated with each station, said yarn control means at each of said stations acting to guide yarns moved to inactive positions thereat to the severing means associated with another of said stations for severence, and acting to guide yarns moved to active position thereat to the severing means associated therewith for severance.

2. In a circular knitting machine having a rotarily operated circle of needles, a plurality of knitting stations, guide fingers for feeding yarns to said needles at each of said stations, and means at each of said stations for moving said fingers thereat between active positions in which said fingers feed their yarns to said needles and inactive positions, in combination with means for severing yarns associated with each station, means associated with each station for guiding yarns moved to active positions thereat to the severing means associated with the same station for severance, and means associated with each station for guiding yarns moved into inactive position thereat to the severing means associated with another of said stations for severance.

3. in a machine according to claim 2 in which said severing means includes a cutting member associated with all of said stations and a cutting element individually associated with each of said stations cooperating with said cutting member.

4. In a machine according to claim 3 in which said cutting member is adapted for rotation with said circle of needles and acts to carry yarns moved to active position at one of said stations to the cutting element associated with said one station for severance and to carry yarns moved to inactive positions at said one station to the cutting element associated with another of said stations.

5. In a machine according to claim 4 in which the yarns moved to inactive positions at said one station are carried by said cutting member to the element associated with the station next adjacent to said one station.

6. In a circular knitting machine having a rotarily operated circle of needles, a plurality of knitting stations, guide fingers for feeding yarns to said needles at each of said stations, and means at each of said stations for moving said fingers thereat between active positions in which said fingers feed their yarns to said needles and inactive positions, in combination with means associated with each of said stations for severing yarns, means at each of said stations for holding the ends of yarns extending from said fingers when moved to inactive positions thereat, means associated with each of said stations for guiding yarns moved to active positions thereat while so held by said holding means to the severing means associated with the same station for severance, and means associated with each of said stations for guiding yarns moved to inactive positions thereat to the severing means associated with another of said stations for severance.

7. In a machine according to claim 6 in which said holding means for said yarns at each of said stations comprises a tube having a lower open end adjacent said station and there is means for causing air to flow into said open end to hold the ends of the inactive yarns therein.

8. In a machine according to claim 7 in which the lower end of said tube for holding the yarns at each of said stations is positioned at the station whereby the ends or" said inactive yarns are held at a point closely adjacent to a radial line extending from the center of said circle of needles through the center of said station.

9. In a machine according to claim '7 in which said means for causing air to flow into said open end of said tube comprises a vacuum pump.

10. In a machine according to claim 9 in which the tube at each of said stations is connected to a common manifold and said manifold is connected to said vacuum pump through a chamber for collecting Waste ends of yarn withdrawn through the tubes at said stations.

References Cited in the file of this patent UNITED STATES PATENTS Stack et al. Feb. 25,

Italy May 13, 

1. IN A CIRCULAR KNITTING MACHINE HAVING A ROTARILY OPERATED CIRCLE OF NEEDLES, A PLURALITY OF KNITTING STATIONS, GUIDE FINGERS FOR FEEDING YARNS TO SAID NEEDLES AT EACH OF SAID STATIONS, AND MEANS FOR MOVING SAID GUIDE FINGERS THEREAT BETWEEN ACTIVE POSITIONS IN WHICH SAID FINGERS FEED THEIR YARN TO SAID NEEDLES AND INACTIVE POSITIONS, IN COMBINATION WITH MEANS FOR SEVERING YARNS ASSOCIATED WITH EACH STATION, AND YARN CONTROL MEANS ASSOCIATED WITH EACH STATION, SAID YARN CONTROL MEANS AT EACH OF SAID STATIONS ACTING TO GUIDE YARNS MOVED TO INACTIVE POSITIONS THEREAT TO THE SEVERING MEANS ASSOCIATED WITH ANOTHER OF SAID STATIONS FOR SEVERENCE, AND ACTING TO GUIDE YARNS MOVED TO ACTIVE POSITION THEREAT TO THE SEVERING MEANS ASSOCIATED THEREWITH FOR SEVERANCE. 